The Guardian of the Solar System (#5.01)

Big Finish, Companion Chronicles

<spoilers galore here>

There are two parts to this story – the first where Robert is
talking with Sara about what has passed since his daughter left and Sara is
telling her story about an enormous clock created by Mavek Chen. The second
part of the story has Sara returning and telling the final part of the story
before she leaves. Robert is now the house! The story has Sara, Stephen, and
the Doctor landing at the clock when they first escape with the M of Terranium.
Sara gets to see Brett Vion and find out about why the clock exists, speaking
to Chen about it.

Meanwhile, Stephen and the Doctor are on their own, being
caught up in the mental trap of the clock. Sara returns and knows what to do
because she knows she is trapped – she must destroy the clock to force Chen to
make the alliance with the Daleks, forcing her to kill her brother who she sees
at this clock location, so he thinks she understands the issue with Chen and
goes to see her and gets himself killed. It’s all wrapped up in Sara’s guilt
for the situation and the feeling of being trapped, even inside the house. And
it all ends with a choice for Sara now – will she enter the TARDIS with another
Doctor inside to perhaps find the answers she’s looking for or stay and just
find a life on this planet.

Wow.
It’s quite the complicated story when it’s laid out like that. And a very good
one. Especially for the narration that Sara is giving to her own story, how she
realizes in hindsight what Mavek Chen is doing to manipulate her and her own
realization of being trapped. It’s a fantastic insight into the mind of Sara
Kingdom, even after her 1000 years or more of life as a house that grants
wishes. Excellent stuff! Very heartening. And the extras are very fun to listen
to as well as Jean Marsh shows how smart and funny she still is, despite being
considerably older than during her run on the show.